This invention relates to wound care covering both external wounds (skin, etc) as well as internal wounds (organs, etc). There are many aspects to wound care, both medical and economic. The shorter the treatment time, the more economical the process and the greater the patient comfort. Treatment and nursing costs are up to 10 times higher than supply costs. Some complications that increase treatment time are infections, non-optimal wound care dressing, longer healing and closure times. These are affected by the wound care system used. The most common wound dressings have been gauze and tape. Subsequently, multi-layered systems have been designed with a film backing. Liquid bandages that provide a film covering of the wound have been developed. These wound coverings provide some of the desired protection to wounds, but do not provide the optimal environment for enhanced wound healing and minimal scarring.
Gauze dressings may not completely protect the wound from water, bacteria, dirt, external oxygen and other foreign matter. Gauze can stick to wounds causing wound damage during dressing changes, increasing the probability of infection and lengthening healing time.
Multi-layered dressings are an improvement over gauze dressings, however they can be stiff and bulky, can be susceptible to channeling permitting bacteria and foreign material to enter wounds. Generally these dressing have a layer for absorbing wound exudate and need to be changed during wound healing. Damage can occur to the wound due to sticking of the dressing to the wound. These multi-layered dressings can have a film backing. Typically polyurethane is used. It does not provide the desired barrier to external oxygen to protect the wound from the external oxygen during the early stages of healing. Some multi-layered dressings may provide some low level of oxygen barrier due to the dressing and its thickness.
Liquid bandages are usually polymer solutions dissolved in organic solvents. The solution is applied directly to the wound, the solvent is evaporated and or precipitated, or the solution is coagulated in situ leaving a film covering over the wound. These films can be nitrocellulose polymers or cyanoacrylates. These films do not provide oxygen barrier properties to the wound site. Since they are not elastomers, they do not provide elasticity and recovery to the film. Due to their high softening temperatures they do not permit the film to flow as a result of the skin/body heat. The nitrocellulose films have a tendency to form cracks when placed on a site that is flexing, eg. Base of the thumb or any other anatomical body part that has movement. These cracks then destroy the protective covering of the wound. These films can also give off undesirable chemical oders. None of the above wound coverings provide all of the desired combination of properties needed for enhanced wound healing such as oxygen barrier, elasticity and recovery, low glass transition temperatures for improved conformity to the site, non-sticking to the wound due to enzyme degradation of the polymer at the wound site giving off carbon dioxide and water.
Other polymeric film coverings may be used such as polyvinylidene chloride and polyvinyl alcohol which can be oxygen barriers. However they have critical limitations. They are not elastomeric polymers with low glass transition temperatures therefore wound not provide films with the needed elasticity and recovery. Polyvinyl alcohol is water soluble and when wet loses its oxygen barrier properties. Polyvinylidene chloride being primarily a crystalline polymer has a high temperature melting and softening point therefore skin and body temperatures are too low to promote flow of the polymer to provide optimum conformity to anatomical body shapes.
Polycarbonates have been given as one of many polymers to be used as a film. They do not work as is taught in this application. Polycarbonates are different polymers than polyalkylene carbonates.
Almost every phase of the healing process is significantly affected by products used to cover the wound, and the resulting environment. (Nemeth A J et al. “Faster healing and less pain in skin biopsy sites treated with an occlusive dressing. Arch Dermatol 1991; 127:1679–83)
In wounds, new blood vessels grow from zones rich in oxygen toward those with less oxygen.(Knighton D et al. “Oxygen tension regulates the expression of angiogenesis factor by macrophages”. Science 1983 221:1283–5) Normal tissue has an oxygen tension of about 40 mm of Hg. Angiogenesis are stimulated at about 1–10 mmHg relatively hypoxic conditions. (Hunt T K, et al. “Wound microenvironment in Cohen IK et al. (eds) Wound healing: Biochemical and Clinical Aspects.” Philadelphia, W B Saunders, 1992, pp 274–281); and (Pai MP et al. “Effect of varying oxygen tensions on healing of open wounds.” Surg Gynecol Obstet 1972; 135: 756–758); and (Storch T G et al. “Oxygen concentration regulates the proliferation responses of human fibroblast to serum and growth factors. Exp Cell Res 1988; 175: 317–325)
Oxygen impermeable dressings to outside oxygen cause angiogenesis to proceed most rapidly. Early oxygen deprevation and later oxygen supplemation are conducive to healing. Reduced wound pH also contributes to angiogenisis. A low pH is maintained by preventing wound tissues from losing all of their carbon dioxide.Some of the problems related to certain wound care systems in prior art methods include:                non-optimal (higher) gaseous oxygen environment around the wound as a result of wound dressings permitting outside oxygen to enter the wound area in the early stages.        lack of proper (adequate) moisture.        bacterial invasion into wound area due to poor bandage adhesion and or coverage, and film coverings which are not elastic and therefor form cracks, channels and wrinkles leading to the wound.        non-optimal removal of exudate related to insufficient water vapor transmission from the wound.        improper mechanical pressures on wound.        gauze bandages can be contaminated from handling, stick to wounds and cause damage to the cells in the healing process during dressing changes by peeling off epidermal cells and interfering with healing        stiff dressings which maybe flexible but are not elastic so as to conform tightly to body shapes during movement.        loss of carbon dioxide from wound tissues leading to high ph and alkalosis        skin sensitivity to tapes causing rashes        chemical odors of varying degrees        other film dressings do not incorporate all of the key properties needed in a solitary film.        
This invention provides an interactive wound care system that solves the above problems. The system provides an occlusive covering and interaction with the wound during the healing process, providing the optimum gas and liquid environment for enhancing wound healing, improving patient comfort and reducing costs.